Sigil Captain, Rosie Cotton of South Lane, Crystalline Crawler, Ooze Flux, and Pir, Imaginative Rascal

Prerequisites

• Sigil Captain on the battlefield
• Rosie Cotton of South Lane on the battlefield
• Crystalline Crawler on the battlefield
• Ooze Flux on the battlefield
• Pir, Imaginative Rascal on the battlefield
• You have at least one +1/+1 counter on a creature you control
• available

Steps

1. Activate Ooze Flux by paying and removing a +1/+1 counter from a creature you control, creating a 1/1 Ooze creature token
2. Rosie Cotton of South Lane triggers, putting two +1/+1 counters on Crystalline Crawler due to Pir
3. When the Ooze enters the battlefield, Sigil Captain triggers, putting four +1/+1 counters on it due to Pir
4. Activate Crystalline Crawler's first ability twice by removing two +1/+1 counters from it, adding
5. Repeat
6. Once you have infinite Oozes with a +1/+1 counter on them, you may remove those counters to create an infinitely large Ooze using Ooze Flux

Results

• Infinite creature tokens
• Infinite ETB
• Infinitely large Ooze token